The present invention realtes to a device comprising at least one magnetoresistor contained in a housing for sensing the position of a ferromagnetic part moving past the magnetoresistor. The magnetoresistor's resistance is influenced by a permanent magnet.
Such a device is described in Valvo Technische Information 840323. It contains a sensor and a permanent magnet attached to the object that moves past the sensor, the latter consisting of magnetoresistors contained in a housing. To achieve high sensitivity, the distance between the magnetoresistors and the passing part, in this case the permanent magnet, should be small. The short distance makes it necessary for the housing wall protecting the magnetoresistors to be correspondingly thin. However, such a thin wall can be easily dented, thereby destroying the magnetoresistors which are deposited on a fragile substrate on the housing wall.